This invention is concerned with a simple, low-cost system for de-salting fuel oil, particularly biodiesel, supplied to gas turbine engines, particularly marine gas turbine engines of the type used in propulsion systems for ships.
In response to rising costs and environmental concerns associated with traditional fossil fuels, fuel-dependent industries are turning to biodiesel to power gas turbine engines. In the implementation of a biodiesel program, it became apparent that salinity found in biodiesel is a significant problem. Salinity reduces the lifespan of gas turbine engines. The normal lifespan of a gas turbine engine burning fuel with an optimal level of salinity of less than 0.1 ppm is 25,000 hours. When the salinity is increased to 0.2 ppm, the maximum concentration for commercial use, the lifespan is reduced by 50%, and at 0.7 ppm there is a 90% reduction in lifespan.
Early in the program of using biodiesel to power marine gas turbine engines, it was discovered that the salinity level of fuel intended for use was in the range of 5-11.5 ppm, which is unacceptable. Such high salinity content renders the fuel unsuitable for use by gas turbine engines.
While processes exist in the prior art for de-salting fuel oil, they are expensive and impractical for use in de-salting fuel to power marine gas turbine engines. Such engines burning 100% biodiesel (a 99.9% biodiesel, 0.1% palm oil blend mix) require an optimal level of salinity of less than 0.1 ppm. The present invention provides a biodiesel fuel having the required characteristics.